/**
 * @param {character[]} s
 * @return {void} Do not return anything, modify s in-place instead.
 */

// 使用了双指针的方法
var reverseString = function(s) {
    let left = 0;
    let right = s.length-1;
    while(left<right) {
        let tmp = s[left];
        s[left] = s[right];
        s[right] = tmp;
        left++;
        right--;
    }
    return s;
};